Question

在我的JS中，我有一个名为box_object的对象。它看起来像这样：

({  id:"3",
    text:"this is a box object",
    connection_parent:["1", "2"],
    connection_child:["5", "6"],
    connectiondata_child:{
        0:{id:"5", linepoint:"bottom"},
        1:{id:"6", linepoint:"bottom"}},
    connectiondata_parent:{
        0:{id:"1", linepoint:"top"},
        1:{id:"2", linepoint:"top"}}
})

现在，我想为box_object.connectiondata_parent添加一些位置值。使用jQuery我可以使用.each（）方法。所以我尝试了，但它失败了。在我的功能中，我执行以下操作：

$(box_object.connectiondata_parent).each(function(it, obj){
    if(typeof(obj[it]) != "undefined" && obj[it].linepoint == "top"){
        var point_position_top = new Object();
        point_position_top.left = startingpoint_left;
        point_position_top.top = startingpoint_top;
        obj[it].position = point_position_top;
    }else if(typeof(obj[it]) != "undefined" && obj[it].linepoint == "bottom"){
        var point_position_bottom = new Object();
        point_position_bottom.left = startingpoint_left;
        point_position_bottom.top = startingpoint_bottom;
        obj[it].position = point_position_bottom;
    }else{}
});

在函数之后我的box_object看起来像这样：

({ id:"3",
   text:"this is third box",
   connection_parent:["1", "2"],
   connection_child:["5", "6"],
   connectiondata_child:{
      0:{id:"5", linepoint:"bottom"},
      1:{id:"6", linepoint:"bottom"}},
   connectiondata_parent:{
      0:{id:"1", linepoint:"top", position:{left:500, top:104}},
      1:{id:"2", linepoint:"top"}}
})

似乎它只将值写入第一个“值”。为什么呢？

Answer 1

根据here的评论Karl Swedberg，$(selector).each()

这应该用于DOM元素。对于普通对象或数组，请使用 jQuery.each()

也许这就是给你一个问题的原因。

Answer 2

以下代码示例不是使用每个功能的框架，而是迭代嵌套元素中的正确条目并执行请求的转换。

function assert(cond, msg) {
  if (!cond) {
    throw msg + " ... failed";
  }
}

// assumed globals
var startingpoint_left   = 500;
var startingpoint_top    = 104;
var startingpoint_bottom =  50; // never shown in sample but referenced                                                         
var idx;

for (idx in box_object.connectiondata_parent) {
  if (box_object.connectiondata_parent.hasOwnProperty(idx)) {
    if (box_object.connectiondata_parent[idx]) {
      box_object.connectiondata_parent[idx].position = {
        "left": startingpoint_left,
        "top":  box_object.connectiondata_parent[idx].linepoint === "top" ? startingpoint_top : startingpoint_bottom
      };
    }
  }
}

assert(box_object.connectiondata_parent[0].position.top  === 104, "index 0 top ");
assert(box_object.connectiondata_parent[0].position.left === 500, "index 0 left");
assert(box_object.connectiondata_parent[1].position.top  === 104, "index 1 top ");
assert(box_object.connectiondata_parent[1].position.left === 500, "index 1 top ");

JS：对象迭代失败

2 个答案: